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Reductions in induced drag by the use of aft swept wing tips

Published online by Cambridge University Press:  04 July 2016

C. W. Burkett*
Affiliation:
Department of Aeronautics and AstronauticsUniversity of Southampton

Summary

Recent experimental and computational studies have indicated that rearward curvature of a wing can reduce the induced drag factor to values less than that obtained from the unswept elliptical wing considered optimal in classical wing theory. Wake non-planarity associated with a wing with aft swept tips has been suggested as a reason for this behaviour. This paper provides a systematic examination of the wake non-planarities induced by a variety of wing planforms and quantifies the induced drag reductions which may be expected. Results suggest a dependence of induced drag factor upon angle of attack, and therefore upon lift coefficient. The crescent wing is identified as the planform to derive the most benefit from its non-planar wake shape, typically a 4% reduction in induced drag factor at moderate angle of attack.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1989 

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References

1. Prandtl, L. Applications of Modern Hydrodynamics to Aeronautics. NACA Report 116, 1921.Google Scholar
2. Munk, M. M. The Minimum Induced Drag of Aerofoils. NACA Report 121, 1921.Google Scholar
3. Kuchemann, D. The Aerodynamic Design of Aircraft. Pergamon Press, 1978.Google Scholar
4. Zimmer, H. The Aerodynamic Optimisation of Wings at Subsonic Speeds and the Influence of Wingtip Design. NASA TM-88534, 1987.Google Scholar
5. Van Dam, C. P. Swept Wing-Tip Shapes for Low-Speed Airplanes. SAE Paper 851770, 1986.Google Scholar
6. Vijgen, P. M. H. W., Van Dam, C. P. and Holmes, B. J. Sheared Wing-Tip Aerodynamics: Wind-Tunnel and Computational Investigations of Induced-Drag Reduction. AIAA Paper 87-2481, Applied Aerodynamics Conference, Monterey, CA, 17-19 Aug, 1987.Google Scholar
7. Van Dam, C. P. Induced-drag characteristics of crescent-moon-shaped wings. J Aircr, Feb. 1987, 24, (2), pp 115119.Google Scholar
8. Cone, C. D. Jr The Theory of Induced Lift and Minimum Induced Drag of Nonplanar Lifting Systems. NASA TR R-139, 1962.Google Scholar
9. Lundry, J. L. A Numerical Solution for the Minimum Induced Drag, and the Corresponding Loading, of Nonplanar Wings. NASA CR-1218, 1968.Google Scholar
10. Hoerner, S. F. Fluid-Dynamic Drag. Published by the author, Box 342, Brick Town, NJ 08273, USA, 1965.Google Scholar
11. Mangler, W. Die Auftriebsverteilung am Tragflugel mit seitlichen Scheiben. Luftfahrt-Forschung, Herausgegeben von der Zentrale fur Wissenschaftliches Berichtswesen der Luftfahr- tforschung des Generalluftzeugmeisters, Berlin-Aldershof, Bd. 16, 219-228, 20. Mai 1939, Verlag von R. Oldenbourg, Munchen/Berlin, 1939.Google Scholar